Merge branch 'task/binary-search-leaf' of github.com:PreetamSing/merkletreejs into PreetamSing-task/binary-search-leaf

This commit is contained in:
Miguel Mota 2022-11-10 05:32:29 -08:00
commit 8433273481
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3 changed files with 152 additions and 26 deletions

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@ -10,7 +10,7 @@ export class Base {
*tree.print()
*```
*/
print ():void {
print (): void {
Base.print(this)
}
@ -26,9 +26,103 @@ export class Base {
*const index = tree.bufferIndexOf(haystack, needle)
*```
*/
protected _bufferIndexOf (array: Buffer[], element: Buffer):number {
protected _bufferIndexOf (
array: Buffer[],
element: Buffer,
isSorted: boolean = false
): number {
if (isSorted) {
return this.binarySearch(array, element, Buffer.compare)
}
const eqChecker = (buffer1, buffer2) => buffer1.equals(buffer2)
return this.linearSearch(array, element, eqChecker)
}
/**
* binarySearch
* @desc Returns the first index of which given item is found in array using binary search.
* @param {Buffer[]} array - Array of items.
* @param {Buffer} element - Item to find.
* @param {Function} compareFunction
* @return {Number} - Index number
*
* @example
* ```js
*const index = MerkleTree.binarySearch(array, element, Buffer.compare)
*```
*/
static binarySearch (
array: Buffer[],
element: Buffer,
compareFunction: (a: unknown, b: unknown) => number
): number {
let start = 0
let end = array.length - 1
// Iterate while start not meets end
while (start <= end) {
// Find the mid index
const mid = Math.floor((start + end) / 2)
// Check if the mid value is greater than, equal to, or less than search element.
const ordering = compareFunction(array[mid], element)
// If element is present at mid, start iterating for searching first appearance.
if (ordering === 0) {
// Linear reverse iteration until the first matching item index is found.
for (let i = mid - 1; i >= 0; i--) {
if (compareFunction(array[i], element) === 0) continue
return i + 1
}
return 0
} /* Else look in left or right half accordingly */ else if (ordering < 0) {
start = mid + 1
} else {
end = mid - 1
}
}
return -1
}
/**
* binarySearch
* @desc Returns the first index of which given item is found in array using binary search.
* @param {Buffer[]} array - Array of items.
* @param {Buffer} element - Item to find.
* @param {Function} compareFunction
* @return {Number} - Index number
*
* @example
* ```js
*const index = tree.binarySearch(array, element, Buffer.compare)
*```
*/
binarySearch (
array: Buffer[],
element: Buffer,
compareFunction: (a: unknown, b: unknown) => number
): number {
return Base.binarySearch(array, element, compareFunction)
}
/**
* linearSearch
* @desc Returns the first index of which given item is found in array using linear search.
* @param {Buffer[]} array - Array of items.
* @param {Buffer} element - Item to find.
* @param {Function} eqChecker
* @return {Number} - Index number
*
* @example
* ```js
*const index = MerkleTree.linearSearch(array, element, (a, b) => a === b)
*```
*/
static linearSearch (array: Buffer[], element: Buffer, eqChecker: (a: unknown, b: unknown) => boolean):number {
for (let i = 0; i < array.length; i++) {
if (element.equals(array[i])) {
if (eqChecker(array[i], element)) {
return i
}
}
@ -36,6 +130,23 @@ export class Base {
return -1
}
/**
* linearSearch
* @desc Returns the first index of which given item is found in array using linear search.
* @param {Buffer[]} array - Array of items.
* @param {Buffer} element - Item to find.
* @param {Function} eqChecker
* @return {Number} - Index number
*
* @example
* ```js
*const index = tree.linearSearch(array, element, (a, b) => a === b)
*```
*/
linearSearch (array: Buffer[], element: Buffer, eqChecker: (a: unknown, b: unknown) => boolean):number {
return Base.linearSearch(array, element, eqChecker)
}
/**
* bufferify
* @desc Returns a buffer type for the given value.
@ -47,7 +158,7 @@ export class Base {
*const buf = MerkleTree.bufferify('0x1234')
*```
*/
static bufferify (value: any):Buffer {
static bufferify (value: any): Buffer {
if (!Buffer.isBuffer(value)) {
// crypto-js support
if (typeof value === 'object' && value.words) {
@ -81,8 +192,8 @@ export class Base {
*console.log(MerkleTree.isHexString('0x1234'))
*```
*/
static isHexString (v: string):boolean {
return (typeof v === 'string' && /^(0x)?[0-9A-Fa-f]*$/.test(v))
static isHexString (v: string): boolean {
return typeof v === 'string' && /^(0x)?[0-9A-Fa-f]*$/.test(v)
}
/**
@ -95,7 +206,7 @@ export class Base {
*MerkleTree.print(tree)
*```
*/
static print (tree: any):void {
static print (tree: any): void {
console.log(tree.toString())
}
@ -109,7 +220,7 @@ export class Base {
*const hexStr = tree.bufferToHex(Buffer.from('A'))
*```
*/
bufferToHex (value: Buffer, withPrefix: boolean = true):string {
bufferToHex (value: Buffer, withPrefix: boolean = true): string {
return Base.bufferToHex(value, withPrefix)
}
@ -123,8 +234,10 @@ export class Base {
*const hexStr = MerkleTree.bufferToHex(Buffer.from('A'))
*```
*/
static bufferToHex (value: Buffer, withPrefix: boolean = true):string {
return `${withPrefix ? '0x' : ''}${(value || Buffer.alloc(0)).toString('hex')}`
static bufferToHex (value: Buffer, withPrefix: boolean = true): string {
return `${withPrefix ? '0x' : ''}${(value || Buffer.alloc(0)).toString(
'hex'
)}`
}
/**
@ -138,7 +251,7 @@ export class Base {
*const buf = tree.bufferify('0x1234')
*```
*/
bufferify (value: any):Buffer {
bufferify (value: any): Buffer {
return Base.bufferify(value)
}
@ -153,7 +266,7 @@ export class Base {
*const fn = tree.bufferifyFn((value) => sha256(value))
*```
*/
bufferifyFn (f: any):any {
bufferifyFn (f: any): any {
return (value: any): Buffer => {
const v = f(value)
if (Buffer.isBuffer(v)) {
@ -173,7 +286,12 @@ export class Base {
}
// crypto-js support
return Buffer.from(f(CryptoJS.enc.Hex.parse(value.toString('hex'))).toString(CryptoJS.enc.Hex), 'hex')
return Buffer.from(
f(CryptoJS.enc.Hex.parse(value.toString('hex'))).toString(
CryptoJS.enc.Hex
),
'hex'
)
}
}
@ -188,7 +306,7 @@ export class Base {
*console.log(MerkleTree.isHexString('0x1234'))
*```
*/
protected _isHexString (value: string):boolean {
protected _isHexString (value: string): boolean {
return Base.isHexString(value)
}
@ -198,7 +316,7 @@ export class Base {
* @param {Number} value
* @return {Number}
*/
protected _log2 (n: number):number {
protected _log2 (n: number): number {
return n === 1 ? 0 : 1 + this._log2((n / 2) | 0)
}
@ -215,7 +333,7 @@ export class Base {
*console.log(zipped) // [ [ 'a', 'A' ], [ 'b', 'B' ] ]
*```
*/
protected _zip (a: any[], b: any[]):any[][] {
protected _zip (a: any[], b: any[]): any[][] {
return a.map((e, i) => [e, b[i]])
}
}

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@ -256,7 +256,7 @@ export class MerkleTree extends Base {
}
}
return this.leaves.filter(leaf => this._bufferIndexOf(values, leaf) !== -1)
return this.leaves.filter(leaf => this._bufferIndexOf(values, leaf, this.sortLeaves) !== -1)
}
return this.leaves
@ -518,13 +518,7 @@ export class MerkleTree extends Base {
const proof = []
if (!Number.isInteger(index)) {
index = -1
for (let i = 0; i < this.leaves.length; i++) {
if (Buffer.compare(leaf, this.leaves[i]) === 0) {
index = i
}
}
index = this._bufferIndexOf(this.leaves, leaf, this.sortLeaves)
}
if (index <= -1) {
@ -870,7 +864,7 @@ export class MerkleTree extends Base {
els = els.sort(Buffer.compare)
}
let ids = els.map((el) => this._bufferIndexOf(this.leaves, el)).sort((a, b) => a === b ? 0 : a > b ? 1 : -1)
let ids = els.map((el) => this._bufferIndexOf(this.leaves, el, this.sortLeaves)).sort((a, b) => a === b ? 0 : a > b ? 1 : -1)
if (!ids.every((idx) => idx !== -1)) {
throw new Error('Element does not exist in Merkle tree')
}
@ -993,7 +987,7 @@ export class MerkleTree extends Base {
if (leaves.every(Number.isInteger)) {
ids = [...leaves].sort((a, b) => a === b ? 0 : a > b ? 1 : -1) // Indices where passed
} else {
ids = leaves.map((el) => this._bufferIndexOf(this.leaves, el)).sort((a, b) => a === b ? 0 : a > b ? 1 : -1)
ids = leaves.map((el) => this._bufferIndexOf(this.leaves, el, this.sortLeaves)).sort((a, b) => a === b ? 0 : a > b ? 1 : -1)
}
if (!ids.every((idx: number) => idx !== -1)) {

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@ -20,3 +20,17 @@ test('bufferifyFn', t => {
t.deepEqual(fn('0x123'), Buffer.from('123', 'hex'))
t.deepEqual(fn('XYZ'), Buffer.from('XYZ'))
})
test('binarySearch', t => {
t.plan(3)
const base = new Base()
const compareFunction = (a, b) => {
if (a === b) return 0
else if (a < b) return -1
else return 1
}
t.equal(base.binarySearch([2, 2, 3, 3, 3, 4, 4, 4, 4], 3, compareFunction), 2)
t.equal(base.binarySearch([3, 3, 3, 3, 3, 4, 4, 4, 4], 3, compareFunction), 0)
t.equal(base.binarySearch([2, 2, 3, 3, 3, 4, 4, 4, 4], 1, compareFunction), -1)
})